At the moment, I'm going to say this game definitely needs instructions to explain in more detail what the unit stats mean and preferably provide a little description about each of the units.

I'd also like it more if it didn't ask me if I wanted to join the match when I was the only one playing, but I'll let you worry about how to fix that because I'm too tired and I'm in player mode right now.

I also think the projectiles move too fast.

And you need to inform people somewhere that projectiles don't travel through walls.

While the range-visibility upon selection is great, I do not like having the upgrade/delete options appearing on top of it. I would much rather this be off to the side somewhere, perhaps next to the unit's stats.

The lives/gold display should not scroll up with the unit selection list.

There should be some obvious display to show you what level a unit is.